In vivo visualization of blood vessels in mouse ear by photoacoustic microscopy with transmissive liquid-crystal adaptive optics
In vivo visualization of blood vessels in mouse ear by photoacoustic microscopy with transmissive liquid-crystal adaptive optics
复制标题
利用透射液晶自适应光学器件的光声显微镜对小鼠耳内血管进行体内可视化
DOI：
10.1117/12.2545777
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Yamaoka Y
中科院分区：
文献类型：
--
作者：
Notsuka Y;Kurihara M;Hashimoto N;Takahashi E;Yamaoka Y
光声显微镜（PAM）是一种生物可视化技术，可以提供活体组织深层结构的高空间分辨率和高对比度图像。然而，由于物镜的球差以及样品表面形状和光散射引起的波前畸变，获得的深部组织光声图像有时会模糊或失真。为了解决这一问题，我们开发了一种采用透射式液晶自适应光学元件的PAM。AO元件的透射式和薄型结构可以方便地安装在PAM系统中。利用通过玻璃基板（厚度为1.5 mm）测量的USAF 1951分辨率测试靶的光声图像，在使用闪光灯泵浦纳秒脉冲激光器（脉冲宽度为5-ns，波长为500-nm）和水浸物镜（NA = 0.8）的情况下，估计了有AO元件和没有AO元件时PAM的横向分辨率。通过优化AO校正，PAM在1.5 mm深度处的横向分辨率由1.04±0.04 μm提高到0.53±0.10 μm。我们也用PAM和AO校正在体内观察了小鼠耳内的小血管。因此，通过根据成像深度优化AO校正，我们提出的PAM提高了生物组织中的空间分辨率。
Photoacoustic microscopy (PAM) is a biological visualization technique that can provide high spatial resolution and high contrast images of deep structures in living tissues. However, because of the spherical aberration of the objective lens and the wavefront distortion due to the surface shape and light scattering of the specimen, obtained photoacoustic images in deep tissues are sometimes blurred or distorted. In order to solve this problem, we have developed a PAM using a transmissive liquid-crystal adaptive optics (AO) element. The transmissive and thin structure of the AO element can be easily installed in the PAM system. Using photoacoustic images of a USAF 1951 resolution test target measured through the glass substrate (thickness; 1.5-mm), the lateral resolutions in PAM were estimated with and without the AO element, when a flashlamp-pumped nanosecond pulse laser (pulse width, 5-ns; wavelength, 500-nm) and water-immersion objective lens (NA = 0.8) were employed. The lateral resolution of PAM at the depth of 1.5-mm was improved from 1.04 ± 0.04 μm to 0.53 ± 0.10 μm by optimizing AO corrections. We have also visualized small blood vessels in mouse ear in vivo by PAM with AO correction. Thus, by optimizing the AO correction according to the imaging depth, our proposed PAM improves the spatial resolution in biological tissues.